sorting array of keys of nsdictionary based on value of nsdictionary

snippet.m

NSDictionary *original = @{
        @"Campo de Teste" : @{@"order" : @"1"},
        @"Alguma coisa" : @{@"order" : @"4"},
        @"outro teste" : @{@"order" : @"2"},
        @"fala cara" : @{@"order" : @"3"},
    };

NSArray *sortedArray;

sortedArray = [original.allKeys sortedArrayUsingComparator:^NSComparisonResult(NSString *a, NSString *b) {
  NSDictionary *dfirst = original[a];
  NSDictionary *dsecond = original[b];
       
  NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
  [f setNumberStyle:NSNumberFormatterDecimalStyle];
       
    NSNumber *first = [f numberFromString:dfirst[@"order"]];
    NSNumber *second = [f numberFromString:dsecond[@"order"]];
    return [first compare:second];
  }];

NSLog(@"%@", sortedArray);